Method and apparatus for supporting positioning for terminals in a wireless network

ABSTRACT

Techniques for supporting positioning for a terminal (sometimes referred to herein as a target device) in a wireless network are described. In an aspect, positioning for a target device includes receiving a Request Location Information message that indicates at least one positioning method from a plurality of supported positioning methods. The Request Location Information message comprises common parameters that are applicable to all positioning methods indicated in the Request Location Information message. The common parameters comprise a quality-of-service (QoS), an indication of whether periodic location information is requested, an indication of whether triggered location information is requested, or any combination thereof. Positioning is performed in response to the Request Location Information message and can include determining a location estimate for a location of the target device.

This is a continuation application of U.S. patent application Ser. No.15/411,244, filed Jan. 20, 2017, which is a continuation application ofU.S. patent application Ser. No. 15/227,766, filed Aug. 3, 2016, whichis a continuation application of U.S. patent application Ser. No.12/763,962, filed Apr. 20, 2010, which claims the benefit of priority toU.S. Provisional Patent Application Ser. No. 61/171,398, entitled “LPPGeneric Capabilities,” filed Apr. 21, 2009, U.S. Provisional PatentApplication Ser. No. 61/172,719, entitled “LPP Stage 2,” filed Apr. 25,2009, U.S. Provisional Patent Application Ser. No. 61/218,929, entitled“LPP,” filed Jun. 20, 2009, U.S. Provisional Patent Application Ser. No.61/234,282, entitled “LPP,” filed Aug. 15, 2009, and Provisional PatentApplication Ser. No. 61/247,363, entitled “LPP,” filed Sep. 30, 2009,each of which is assigned to the Assignee hereof and expresslyincorporated herein by reference.

BACKGROUND

I. Field

The present disclosure relates generally to communication, and morespecifically to techniques for supporting positioning for terminals in awireless network.

II. Background

It is often desirable, and sometimes necessary, to know the location ofa terminal, e.g., a cellular phone. The terms “location” and “position”are synonymous and are used interchangeably herein. For example, alocation services (LCS) client may desire to know the location of theterminal and may communicate with a network server in order to requestfor the location of the terminal. The network server and the terminalmay then exchange messages, as necessary, to obtain a location estimatefor the terminal. The network server may then return the locationestimate to the LCS client.

Different terminals may operate in different scenarios and may havedifferent capabilities with regard to positioning. Positioning refers toa functionality that determines a geographical location of a targetterminal. It may be desirable to flexibly support positioning forterminals with different capabilities.

SUMMARY

Techniques for supporting positioning for a terminal (sometimes referredto herein as a target device) in a wireless network are described.

In one aspect, a method for positioning a target device includesreceiving a Request Location Information message that indicates at leastone positioning method from a plurality of supported positioningmethods. The Request Location Information message comprises commonparameters that are applicable to all positioning methods indicated inthe Request Location Information message. The common parameters comprisea quality-of-service (QoS), an indication of whether periodic locationinformation is requested, an indication of whether triggered locationinformation is requested, or any combination thereof. The method furtherincludes performing positioning in response to the Request LocationInformation message.

In one aspect, an apparatus for positioning a target device includes atleast one processing unit and a memory coupled to the at least oneprocessing unit. The memory stores instructions that when executed bythe at least one processing unit cause the at least one processing unitto receive a Request Location Information message that indicates atleast one positioning method from a plurality of supported positioningmethods. The Request Location Information message comprises commonparameters that are applicable to all positioning methods indicated inthe Request Location Information message. The common parameters comprisea quality-of-service (QoS), an indication of whether periodic locationinformation is requested, an indication of whether triggered locationinformation is requested, or any combination thereof The instructionsfurther cause the at least one processing unit to perform positioning inresponse to the Request Location Information message.

In one aspect, a non-transitory computer-readable medium storesinstructions for positioning a target device. The instructions whenexecuted by the one or more processors cause the one or more processorsto receive a Request Location Information message that indicates atleast one positioning method from a plurality of supported positioningmethods. The Request Location Information message comprises commonparameters that are applicable to all positioning methods indicated inthe Request Location Information message. The common parameters comprisea quality-of-service (QoS), an indication of whether periodic locationinformation is requested, an indication of whether triggered locationinformation is requested, or any combination thereof. The instructionsfurther cause the one or more processors to perform positioning inresponse to the Request Location Information message.

Various aspects and features of the disclosure are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of an exemplary deployment supportingpositioning.

FIG. 2A shows a configuration supporting terminal-assisted andterminal-based positioning methods.

FIG. 2B shows a configuration supporting network-based positioningmethods.

FIGS. 2C and 2D show two configurations supporting peer-to-peerpositioning.

FIG. 3 shows a hierarchical structure for a positioning protocol.

FIG. 4A shows a design of a positioning message.

FIG. 4B shows a design of a positioning message with multiple partsdefined by different organizations.

FIG. 5 shows a message flow for a mobile-originated location requestservice.

FIG. 6 shows a message flow for a location session with multipletransactions.

FIGS. 7 to 11 show various processes for supporting positioning.

FIG. 12 shows a block diagram of a target device, a base station, and alocation server.

DETAILED DESCRIPTION

FIG. 1 shows a diagram of an exemplary deployment 100 supportingpositioning. A target device (TD) 110 is an entity whose location is tobe determined. Target device 110 may be stationary or mobile and mayalso be referred to as a terminal, a mobile station, a user equipment(UE), an access terminal, a SUPL enabled terminal (SET) in Secure UserPlane Location (SUPL) from Open Mobile Alliance (OMA), a subscriberunit, a station, etc. Target device 110 may be a cellular phone, apersonal digital assistant (PDA), a wireless device, a wireless modem, awireless router, a laptop computer, a telemetry device, a trackingdevice, etc. Target device 110 may communicate with one or more basestations in a wireless network. Target device 110 may also communicatepeer-to-peer with other terminals.

A reference source (RS) 140 is an entity that transmits a signal (e.g.,a radio signal) that can be measured to support positioning. Referencesource 140 may be a satellite in a Satellite Positioning System (SPS),which may be the United States Global Positioning System (GPS), theEuropean Galileo system, the Russian GLONASS system, or some other SPS.Reference source 140 may also be a base station in a wireless network. Abase station may also be referred to as an access point, a Node B, anevolved Node B (eNB), etc. A wireless network may be a Global System forMobile Communications (GSM) network, a Wideband Code Division MultipleAccess (WCDMA) network, a General Packet Radio Service (GPRS) accessnetwork, a Long Term Evolution (LTE) network, a CDMA 1X network, a HighRate Packet Data (HRPD) network, an Ultra Mobile Broadband (UMB)network, a wireless local area network (WLAN), etc. GSM, WCDMA, GPRS,and LTE are different radio technologies defined by an organizationnamed “3rd Generation Partnership Project” (3GPP). CDMA 1X, HRPD and UMBare different radio technologies defined by an organization named “3rdGeneration Partnership Project 2” (3GPP2). Reference source 140 may alsobe a broadcast station in a broadcast network, which may be a televisionnetwork, a digital broadcast network, etc. Reference source 140 may alsobe part of a terminal, e.g., target device 110. In general, one or moresignals from one or more reference sources may be measured to determinethe location of target device 110. Only one reference source 140 isshown in FIG. 1 for simplicity. The location of a reference source maybe known or can be ascertained and may be used for positioning of targetdevice 110.

A positioning unit (PU) 120 is an entity that can measure signals fromone or more reference sources, such as reference source 140. Positioningunit 120 may also be able to compute a location estimate for targetdevice 110 based on measurements obtained by positioning unit 120.Positioning unit 120 may be part of target device 110, or a separatedevice, or part of some other entity. The other entity may be anotherterminal, a base station, a specialized location measurement unit (LMU)in a wireless network, etc.

A location server (LS) 130 is an entity that can receive positioninginformation for a target device and determine location information forthe target device. In general, positioning information may be anyinformation used to support positioning. For example, positioninginformation may comprise measurements, a coarse location estimate, etc.Location information may be any information related to the location of atarget device. For example, location information may comprise assistancedata for making measurements of signals for positioning, a finallocation estimate for the target device, etc. Location server 130 maycommunicate with positioning unit 120, receive positioning informationfrom positioning unit 120, and provide location information (e.g.,assistance data) to positioning unit 120. Location server 130 may alsocompute a location estimate for target device 110 based on measurementsreceived from positioning unit 120 and provide the location estimate topositioning unit 120. Location server 130 may reside in any one of aplurality of entities. For example, location server 130 may be a ServingMobile Location Center (SMLC), a Standalone SMLC (SAS), an Evolved SMLC(E-SMLC), a SUPL Location Platform (SLP), a Position Determining Entity(PDE), etc. Location server 130 may also be part of a terminal, e.g.,part of target device 110. In one design, location server 130 maycommunicate with other entities (e.g., positioning unit 120) via acommon positioning protocol regardless of where location server 130resides. The common positioning protocol may be LTE Positioning Protocol(LPP) used in LTE or some other positioning protocol.

FIG. 1 shows four generic entities that can support positioning fortarget device 110. Various configurations may be supported by theentities shown in FIG. 1. In one design, target device 110 andpositioning unit 120 may be co-located. In this design, target device110 may measure one or more signals from one or more reference sourcesfor positioning of target device 110. In another design, target device110 and reference source 140 may be co-located. In this design, targetdevice 110 may transmit a signal that may be measured and used forpositioning of the target device. In yet another design, target device110 may be co-located with location server 130. In this design, targetdevice 110 may receive measurements from positioning unit 120 and mayperform positioning for target device 110 based on the measurements. Ingeneral, target device 110 may support positioning unit 120 and/orreference source 140 in order to measure other signals or have its ownsignal measured. Other configurations may also be supported by theentities shown in FIG. 1. For example, positioning unit 120 and locationserver 130 may be co-located. As another example, reference source 140and location server 130 may be co-located.

FIG. 2A shows a configuration supporting terminal-assisted andterminal-based positioning methods. In this configuration, positioningunit 120 is co-located with target device 110. Positioning unit 120 maymeasure signals from reference sources such as a satellite 140 a, a basestation 140 b, etc. Positioning unit 120 may send measurements and/orother information (e.g., a coarse or a fine location estimate) tolocation server 130. Location server 130 may determine locationinformation (e.g., assistance data) and may send the locationinformation to positioning unit 120 (e.g., to assist positioning unit120 to measure signals and possibly obtain a location estimate).Location server 130 may also determine a location estimate for targetdevice 110 based on measurements and/or other information received frompositioning unit 120. Location server 130 may forward the locationestimate to some external client (not shown in FIG. 2A) and/or to targetdevice 110. The configuration in FIG. 2A may be used forterminal-assisted and terminal-based positioning methods such asassisted GNSS (A-GNSS), observed time difference (OTD), enhancedobserved time difference (E-OTD), observed time difference of arrival(OTDOA), advanced forward link trilateration (A-FLT), etc.

FIG. 2B shows a configuration supporting network-based positioningmethods. In this configuration, reference source 140 is co-located withtarget device 110, and positioning unit 120 is external to target device110. Positioning unit 120 may measure a signal from target device 110.Positioning unit 120 may also receive measurements made by target device110 for other reference sources (not shown in FIG. 2B). The measurementsfrom target device 110 may be used to support handover of target device110 and/or for other purposes. Positioning unit 120 may send themeasurements and/or other information to location server 130. Locationserver 130 may determine location information (e.g., assistance data)and may send the location information to positioning unit 120 (e.g., toassist positioning unit 120 to measure signals from reference source140). Location server 130 may also determine a location estimate fortarget device 110 based on measurements and/or other informationreceived from positioning unit 120. Location server 130 may forward thelocation estimate to some external client (not shown in FIG. 2B) and/orto target device 110. The configuration in FIG. 2B may be used fornetwork-based positioning methods such as enhanced cell identity(E-CID), uplink time difference of arrival (U-TDOA), etc.

For simplicity, FIGS. 2A and 2B show one positioning unit 120 and one ormore reference sources 140. In general, any number of positioning unitsmay measure signals from any number of reference sources and may sendtheir measurements to location server 130. Target device 110 may act asa reference source for some measurements and/or as a positioning unitfor other measurements.

FIGS. 2A and 2B show two configurations supporting non peer-to-peer(P2P) positioning. Non-P2P positioning may occur when reference source140, positioning unit 120, and location server 130 are not co-locatedwith (e.g., are not part of) any terminal that is not target device 110.For non-P2P positioning, location server 130 may be a network entity orpart of target device 110, positioning unit 120 may be part of eithertarget device 110 or a network entity, and reference source 140 may bepart of either target device 110 or an external entity (e.g., asatellite, a base station, a broadcast station, etc.)

In one design, P2P positioning may be supported by the entities shown inFIG. 1. P2P positioning may occur when a first terminal assumes the roleof location server 130, or positioning unit 120, or reference source140, or any combination thereof, in order to help position a secondterminal that assumes the role of target device 110. Different types ofP2P positioning may be supported depending on where location server 130,positioning unit 120, and reference source 140 reside, or whether thefirst or second terminal assumes the role of each of the locationserver, the positioning unit, and the reference source.

FIG. 2C shows a configuration supporting P2P positioning. In thisconfiguration, a first terminal 102 is target device 110 and alsoassumes the roles of location server 130 and reference source 140. Asecond terminal 104 communicates peer-to-peer with first terminal 102and assumes the role of positioning unit 120. Positioning unit 120 interminal 104 may measure a signal from reference source 140 in terminal102 and may send measurements and possibly other information to locationserver 130 in terminal 102. Location server 130 may determine locationinformation (e.g., assistance data) and may send the locationinformation to positioning unit 120 (e.g., to assist positioning unit120 to measure signals from reference source 140). Location server 130may also determine a location estimate for target device 110 based onmeasurements and/or other information received from positioning unit120. Location server 130 may forward the location estimate to someexternal client (not shown in FIG. 2C) and/or pass the location estimateto some entity (e.g., an application) in target device 110.

For simplicity, FIG. 2C shows terminal 102 communicating with one peerterminal 104. In general, terminal 102 may communicate with any numberof peer terminals and may request measurements from one or more peerterminals. Each peer terminal may act as a positioning unit and maymeasure the signal from terminal 102. Each peer terminal may sendmeasurements and its location to terminal 102. The location of terminal102 may be determined based on the measurements from all peer terminalsand their reported locations.

FIG. 2D shows another configuration supporting P2P positioning. In thisconfiguration, a first terminal 106 is target device 110 and alsoassumes the roles of positioning unit 120 and location server 130. Asecond terminal 108 communicates peer-to-peer with first terminal 106and assumes the role of reference source 140. Positioning unit 120 interminal 106 may measure a signal from reference source 140 in terminal108 and may send measurements and/or other information to locationserver 130 in terminal 106. Location server 130 may also receive thelocation of terminal 108. Location server 130 may determine locationinformation (e.g., assistance data) and may transfer the locationinformation to positioning unit 120 (e.g., to assist positioning unit120 to measure signals from reference source 140) in terminal 108.Location server 130 may also determine a location estimate for targetdevice 110 based on measurements and/or other information received frompositioning unit 120. Location server 130 may forward the locationestimate to some external client (not shown in FIG. 2D) and/or pass thelocation estimate to some entity (e.g., an application) in target device110.

For simplicity, FIG. 2D shows terminal 106 communicating with one peerterminal 108. In general, terminal 106 may communicate with any numberof peer terminals and may make measurements for one or more peerterminals. Each peer terminal may act as a reference source whose signalmay be measured by terminal 106. Each peer terminal may send itslocation to terminal 106. The location of terminal 106 may be determinedbased on the measurements for all peer terminals and their reportedlocations.

For P2P positioning, the role of positioning unit 120 and locationserver 130 may be assumed by different terminals. To avoid ambiguity, aterminal initiating a location transaction may specify whichend/terminal of the transaction will assume the role of each of thelocation server and the positioning unit. Each terminal may then assumethe role specified by the initiating terminal.

P2P positioning may be used to position a terminal, as described above.P2P positioning may also be used to help position an access point for afemto cell, which may also be referred to as a home Node B (HNB), a homeeNB (HeNB), etc. In this case, the access point may be treated like aterminal.

In one design, generic positioning methods (GPMs) may be used to supportpositioning of target devices. A generic positioning method is apositioning method that supports positioning for a target device withdifferent types of reference sources using the same type of measurementsand location computation procedure.

Table 1 lists some generic positioning methods that may be supported andprovides a short description for each generic positioning method.

TABLE 1 Generic Positioning Methods GPM Description Uplink or Employtime of arrival differences between either (i) signal Downlink of thesame reference source/target device measured at Time differentpositioning units (for uplink) or (ii) signals of Difference differentreference sources measured by a positioning Based GPM unit/target device(for downlink). Use trilateration method to compute location of targetdevice. Propagation Employ measurements of propagation delay from a TimeBased reference source to a positioning unit with one of these GPMentities being at a known location and the other entity being co-locatedwith a target device. Use trilateration method to compute location.Direction Employ measurements of signal direction from a reference BasedGPM source to a positioning unit, where the reference source may be partof the target device and the positioning unit may be part of a network.Use triangulation methods to compute location. Path Loss Employmeasurements of signal strength of a reference Based GPM source at apositioning unit to estimate distance between the reference source andthe positioning unit based on signal attenuation. Can use trilaterationmethod to compute location. RF Pattern Employ measurements of signalstrength of either (i) the Matching same reference source co-locatedwith a target device at GPM different positioning units or (ii)different network-based reference sources at the same positioning unitco-located with the target device. Employ predetermined RF signalstrength patterns over small geographic areas to determine the mostlikely location of the target device based on pattern matching.

Detection of the presence of a particular reference source, withoutmeasurement of a signal from the reference source, may also be includedin one or more generic positioning methods listed in Table 1 to supportcell ID or WLAN-based positioning. A combination of generic positioningmethods may also be used for positioning, e.g., to improve accuracy.

In one design, a set of positioning method classes (PMCs) may bedefined. A PMC may include a set of positioning methods defined byapplying one or more generic positioning methods to a given type ofreference source. Different types of reference sources may be used forpositioning and may include LTE eNBs, LTE-capable terminals, CDMA 1Xbase stations, IX-capable terminals, etc. For a given type of referencesource, one or more specific positioning methods may be defined byapplying one or more generic positioning methods to this referencesource. For example, A-GPS may be obtained by applying downlink timedifference based GPM to GPS reference sources, U-TDOA may be obtained byapplying uplink time difference based GPM to a GSM reference source,E-CID may be obtained by applying direction based and/or RF patternmatching GPM to an LTE reference source, etc.

Each PMC may include one or more positioning methods. The positioningmethods in each PMC may be related because they employ measurements ofthe same type of reference source. These measurements may overlap, andthe same measurements may be usable for different positioning methodswithin the PMC. Assistance data used to enable measurements and/orlocation computation for positioning methods in the same PMC may alsooverlap (e.g., if the measurements also overlap). Overlappingmeasurements and assistance data may be used to more efficiently supportseveral positioning methods within a PMC using a reduced set ofmeasurements and assistance data. For example, measurements andassistance data that apply to multiple positioning methods may betransferred only once instead of for each positioning method.

FIG. 3 shows a hierarchical structure 300 for a positioning protocol,which may be used by location server 130. The positioning protocol maysupport a set of PMCs, which may be defined for different types ofreference sources as described above. Each PMC may include a set of oneor more positioning methods defined for a particular type of referencesource. For example, an A-GNSS PMC may include A-GPS and A-Galileopositioning methods, a downlink LTE PMC may include OTDOA and E-CIDpositioning methods, an uplink LTE PMC may include E-CID positioningmethod, etc. Other PMCs may be defined for downlink WCDMA, uplink WCDMA,downlink CDMA 1X, uplink CDMA 1X, downlink WiMAX, uplink WiMAX, 802.11Wi-Fi, sensors, etc.

A positioning method (PM) may be used to determine the location of atarget device and may be associated with a particular genericpositioning method and/or a particular reference source type. Eachpositioning method may support all or a subset of all measurements andassistance data applicable for its PMC. The set of measurements andassistance data supported by a given positioning method may bemandatory, or optional, or conditional for any positioning unit orlocation server supporting that positioning method.

A positioning unit or a location server that supports a given PMC maysupport at least one positioning method in that PMC. A positioning unitor a location server that supports a given positioning method maysupport all mandatory (and possibly optional and/or conditional)measurements and assistance data for that positioning method.

In one design, a set of measurement data units (MDUs) may be defined forall supported positioning methods. An MDU may be a collection of one ormore items of data that may be used to report measurements and theirattributes. An MDU may be applicable for one or more positioning methodswithin a particular PMC. An MDU may apply to multiple positioningmethods and may be efficiently sent once to provide measurement data tothese positioning methods (instead of separately for each positioningmethod). For example, MDU 2 in FIG. 3 may apply to positioning methodsPMa and PMb and may be sent once for these two positioning methods. AnMDU may apply to one reference source and may be repeated for multiplereference sources of the same type, e.g., to provide or requestpseudo-ranges for multiple satellites, timing differences for multiplebase stations, etc.

MDUs may enable capabilities of location servers and positioning unitsto be defined, e.g., in terms of which MDUs a location server orpositioning unit supports. MDUs may also enable location server 130 torequest and positioning unit 120 to provide measurement data in aflexible and precise manner. Location server 130 may indicate certaincharacteristics (e.g., accuracy and response time) of an MDU whenrequesting it from positioning unit 120. Positioning unit 120 mayindicate the characteristics (e.g., accuracy) of an MDU that it is ableto provide (e.g., via its capabilities).

In one design, a set of assistance data units (ADUs) may be defined forall supported positioning methods. An ADU may be a collection of one ormore items of data that may be used to assist measurements. An ADU maybe applicable for one or more positioning methods within a particularPMC. An ADU may apply to multiple positioning methods and may beefficiently sent once to provide assistance data to these positioningmethods (instead of separately for each positioning method). Forexample, ADU d in FIG. 3 may apply to positioning methods PMd and PMeand may be sent once for these two positioning methods. An ADU may applyto one reference source and may be repeated for multiple referencesources of the same type, e.g., to provide or request ephemeris data formultiple satellites within the same SPS, real time differences (RTDs)for multiple base stations of the same access type, etc.

ADUs may enable capabilities of location servers and positioning unitsto be defined, e.g., in terms of which ADUs a location server orpositioning unit supports. ADUs may also enable positioning unit 120 torequest and location server 130 to provide assistance data in a flexibleand precise manner. Positioning unit 120 may indicate certaincharacteristics of an ADU (e.g., lifetime or accuracy for GPS ephemerisdata) when requesting it from location server 130.

In one design, PMCs, positioning methods, MDUs, and/or ADUs may beindividually identified. This identification may facilitatecapabilities, specific measurements, and specific assistance data to berequested and provided. Identification may also be useful to identifythe presence of a particular MDU or ADU in a positioning message, toidentify a message segment related to a specific positioning method orPMC, etc. The identities of PMCs may be unique across the positioningprotocol whereas the identities of positioning methods, MDUs, and ADUsmay be unique only for a particular PMC. Different ranges of IDs may beused for identification. For example, PMC ID of 0 may be reserved forpossible future signaling applicable to all PMCs, PMC IDs of 1 to 63 maybe used for network-based (uplink) PMCs, PMC IDs of 64 to 127 may beused for terminal-assisted and terminal-based (downlink) PMCs, PMC IDsof 128 to 191 may be used for operator specific positioning methods, PMCIDs of 192 to 254 may be used for vendor specific positioning methods,and PMC ID of 255 may be used to indicate PMC IDs greater than 255, ifneeded. In general, IDs may be defined in any suitable manner for PMCs,positioning methods, MDUs, and/or ADUs.

In one design, calibration PMCs may be used to provide calibration datato a location server for one or more reference sources. Calibration datamay be for (i) signal timing and/or signal strength for base stations,access points, and/or other reference sources, (ii) timing andnavigation data for GNSS systems, and/or (iii) other signals and data.Calibration data may be used by a location server to obtain assistancedata that can be provided later to a positioning unit to assist it inmaking measurements to locate a target device. As an example,calibration data that includes transmission timing differences betweennearby base stations may be used by a location server to deriveassistance data (e.g., including approximate time differences betweennearby base stations that a target device would be expected to measure)for downlink time difference positioning methods such as OTDOA. Suchassistance data may then be sent later to a position unit co-located inthe target device. A calibration PMC (or a calibration positioningmethod) may support a corresponding normal PMC (or normal positioningmethod) as described in the example above by helping obtain assistancedata for the normal PMC (or normal positioning method) and by helping tocompute a location estimate for any positioning method in the normalPMC. For example, a calibration PMC for inter-eNB timing measurement maysupport a downlink LTE PMC including OTDOA and E-CID positioningmethods.

The use of calibration PMCs as part of a common positioning protocolthat also supports normal PMCs may allow the common positioning protocolto be used to calibrate reference sources and thereby avoid the need foradditional protocols for this purpose. A calibration PMC may notdirectly support any positioning methods, any ADUs, and positioning oftarget devices. A calibration PMC may support MDUs, which may beprovided by positioning units (e.g., base stations or LMUs) forreference sources applicable to the corresponding normal PMC. The MDUsmay be used by the location server to help obtain ADUs for thecorresponding normal PMC as well as to help compute a location estimatefor the position methods in the corresponding normal PMC.

In one design, location server 130 and target device 110 (or locationserver 130 and positioning unit 120) may engage in a location session inorder to obtain measurements or location, to provide assistance data,and/or for other purposes. A location session may also be referred to asan LPP session, a positioning session, etc. A location session mayinclude one or more transactions, which may also be referred to as LPPtransactions, etc. Each transaction may cover a particular operationsuch as exchange of capabilities, transfer of assistance data, transferof location information, etc. Each transaction may be assigned atransaction ID, and all messages for that transaction may include thetransaction ID in order to link the messages to the same transaction.

In one design, a set of positioning messages may be defined and used forcommunication between location servers and other entities. Thepositioning messages may also be referred to as LPP messages, LPPprotocol data units (PDUs), etc.

FIG. 4A shows a design of a positioning message 400. In this design,positioning message 400 includes a positioning protocol version field410, a transaction ID field 412, a transaction end flag field 414, amessage type field 416, and N information elements 420 a through 420 n,where N may be zero or greater. Field 410 may indicate which version ofthe positioning protocol is used for a location session and may beincluded to negotiate the use of the same positioning protocol versionby two entities engaging in the location session. An originating entitymay set field 410 to the highest version that it supports. A receivingentity may return the highest version that it supports. The negotiatedversion may be the lower of the two highest versions supported by thetwo entities.

Field 412 may identify a transaction for which the positioning messageapplies. Field 412 may be especially pertinent when multipletransactions occur concurrently during the location session. Eachtransaction may be assigned a unique transaction ID. In one design, anoriginating entity that initiates a transaction may assign a transactionID for that transaction. A responding entity may use the sametransaction ID when responding to the originating entity. For example,location server 130 may assign transaction IDs to transactions initiatedby location server 130, and positioning unit 120 may assign transactionIDs to transactions initiated by positioning unit 120. When more thanone location servers are used to position target device 110, eachlocation server may be allocated a different range of transaction IDsthat can be assigned by that location server.

Field 414 may indicate whether the sending entity has terminated thetransaction. Field 416 may indicate the type of message being sent. Aset of message types may be supported as described below, andpositioning message 400 may be of the type indicated by field 416.

Fields 420 a through 420 n may include information that may be dependenton the message type. Each field 420 may carry a positioning datacomponent (PDC) for one PMC or positioning method. Positioning message400 may include multiple PDCs to efficiently convey information for morethan one PMC at a time and to invoke combined/hybrid positioning.

A positioning message may also include different and/or other fieldsbesides the fields shown in FIG. 4A. For example, a positioning messagemay include a field for session ID, a field to indicate whether thesender is acting as a location server or a positioning unit, etc.

Table 2 lists a set of positioning message types that may be supportedin accordance with one design.

TABLE 2 Positioning Message Type Message Type Description RequestMessage to request for capabilities of an entity for Capabilitiespositioning protocol and positioning methods. Provide Message to providecapabilities of an entity for Capabilities positioning protocol andpositioning methods. Request Message to request for assistance data.Assistance Data Provide Message to provide assistance data. AssistanceData Request Location Message to request for location information.Information Provide Location Message to provide location information.Information

Location server 130 may provide its capabilities when requested bypositioning unit 120 or may send its capabilities unilaterally withoutreceiving any request. Similarly, positioning unit 120 may provide itscapabilities when requested by location server 130 or may send itscapabilities unilaterally without receiving any request. Thecapabilities of an entity (e.g., location server 130 or positioning unit120) may include the PMCs and positioning methods supported by thatentity and the capabilities of the entity for each supported positioningmethod (e.g., a list of MDUs that can be sent or received by the entityand/or a list of ADUs that can be sent or received by the entity).

Location server 130 may provide assistance data when requested bypositioning unit 120 or may send the assistance data unilaterallywithout receiving any request. The assistance data may assistpositioning unit 120 to make measurements that may be used forpositioning of target device 110 or for calibration of reference source140. Location server 130 may also provide assistance data when the datachanges for an ongoing positioning method. This automatic update ofassistance data may enable the positioning method to be reset withouthaving to explicitly abort and restart it. For example, target device110 may change serving cell (e.g., due to handover) during an OTDOApositioning method, and location server 130 may send new assistance dataapplicable for the new serving cell in order for positioning unit 120(in target device 110) to obtain and transfer measurements of differentneighbor base stations associated with the new serving cell. As anotherexample, positioning unit 120 (e.g., an LMU) may measure data and/orsignaling channels transmitted by target device 110 in a particularserving cell for U-TDOA positioning, and target device 110 may changeserving cell (e.g., due to handover). Location server 130 may then sendnew assistance data to positioning unit 120 to enable it to measuredifferent data and/or signaling channels associated with the new servingcell. Having automatic update may be useful in these scenarios.

Positioning unit 120 may send positioning information to location server130 to support positioning of target device 110 (e.g., for a normal PMC)or determination of assistance data for future positioning (e.g., for acalibration PMC). The positioning information may comprise (i)measurements made by positioning unit 120 within target device 110 forother reference sources (e.g., as shown in FIG. 2A), (ii) measurementsmade by positioning unit 120 external to target device 110 for referencesource 140 in target device 110 (e.g., as shown in FIG. 2B), (iii) alocation estimate for target device 110 obtained by positioning unit120, and/or (iv) other information related to the location of targetdevice 110. Location server 130 may send location information comprisinga location estimate for target device 110 to positioning unit 120, e.g.,if positioning unit 120 is part of target device 110 and target device110 is the intended final recipient of the location estimate. Forcalibration of a reference source, positioning information may comprisemeasurements made by positioning unit 120 for network-based referencesources (e.g., base stations) and other resources (e.g., satellites).

A positioning message may also include a field for common parametersapplicable for all PMCs supported by the positioning message. The commonparameters for a Request Capabilities message and a Provide Capabilitiesmessage may include a list of supported PMC IDs, PMC versions, etc. Thecommon parameters for a Request Assistance Data message may include anapproximate location of a target device, an indication of whetherperiodic or triggered assistance data is requested and associatedparameters, primary access (e.g., a serving cell ID), secondary accesses(e.g., neighboring cell IDs), etc. The common parameters for a ProvideAssistance Data message may include an approximate location of a targetdevice, current time, etc. The common parameters for a Request LocationInformation message may include required quality-of-service (QoS) (e.g.,for location, measurement accuracy, and/or response time), an indicationof whether periodic or triggered location information is requested andassociated parameters, location type for terminal-assisted and/orterminal-based positioning methods, a list of required or preferred PMCIDs and PMC versions, etc. The common parameters for a Provide LocationInformation message may include a location estimate and accuracy, time,velocity, etc.

FIG. 4B shows a design of a positioning message 450 that includesmultiple parts defined by different organizations. Positioning message450 may include a positioning protocol version field, a transaction IDfield, a transaction end flag field, a message type field, and Ninformation elements, as described above for FIG. 4A. In one design, onepart may be sent in each information element. For example, a first partmay comprise first information for positioning defined by a firstorganization, a second part may comprise second information forpositioning defined by a second organization, etc. An organization maybe 3GPP, 3GPP2, OMA, Internet Engineering Task Force (IETF), Instituteof Electrical and Electronics Engineers (IEEE), a network operator, anequipment vendor, etc. The multiple parts may be for a particulartransaction type, e.g., capability transfer, assistance data transfer,location information transfer, etc. This design may allow an externalorganization to enhance an existing positioning method or support newpositioning methods by defining additional capabilities that may becarried in one or more additional parts of a positioning message.

In one design, several related transactions may be invoked in parallel.For example, positioning unit 120 may be co-located with target device110 (e.g., as shown in FIG. 2A) and may request for its own locationfrom location server 130, request for assistance data from locationserver 130, and provide its capabilities to location server 130 toenable location server 130 to obtain its location. As another example,positioning unit 120 may be co-located with target device 110 and mayrequest for its own location from location server 130 and may providemeasurements for one or more positioning methods (e.g., E-CID and/orA-GNSS) to location server 130 to enable location server 130 to derive alocation estimate. The messages sent by positioning unit 120 to locationserver 130 in both examples above may also be combined. As yet anotherexample, location server 130 may request for positioning informationfrom positioning unit 120, which may be co-located with target device110, and may provide assistance data to positioning unit 120 to helpobtain the positioning information.

In one design, multiple positioning messages for multiple transactionsmay be transported together in one message transaction/exchange. In onedesign, a single container message may include the multiple positioningmessages. For example, the container message may be a predefinedpositioning message that can carry the multiple positioning messages inmultiple information elements, one information element for eachindividual positioning message. In another design, the multiplepositioning messages may be linked and sent separately, either seriallyor in parallel. A common identifier may be included in each message toenable the separate messages to be associated at a receiving entity. Themultiple positioning messages may also be transported together in othermanners. The format and content of each positioning message may not bedependent on whether that positioning message is sent alone or withother positioning messages.

A sending entity may send a container message including multiplepositioning messages for multiple transactions. A recipient entity maygenerate individual replies for the multiple transactions and may usethe association of the multiple positioning messages to provide moreappropriate responses, e.g., by making use of the information containedin all received positioning messages to generate the reply to eachreceived message. The recipient entity may return a container messageincluding multiple positioning messages for the individual replies.Transporting multiple positioning messages together may provide variousadvantages such as (i) reduce delay and avoid problems due to deliveryof positioning messages out of order if sent separately and (ii) ensurethat a receiving entity is in possession of the most information neededto process and reply to each received message.

FIG. 5 shows a message flow 500 for a mobile-originated location request(MO-LR) service in LTE. An LCS client in a UE 510 or a user of UE 510may request for location service, e.g., to retrieve the location of UE510 or to transfer the UE location to a third party. UE 510 may send anMO-LR request message to a Mobility Management Entity (MME) 540 via aserving eNB 520 (step 1). The MO-LR request message may be used as acontainer message to carry one or more positioning messages to instigateone or more procedures. For example, the MO-LR request message mayinclude a positioning message to provide capabilities of UE 510, apositioning message to request for assistance data, a positioningmessage to provide measurements, etc. MME 540 may send a locationrequest message to an E-SMLC 530 (step 2). The location request messagemay include any positioning message received by MME 540 in step 1.

E-SMLC 530 and UE 510 may engage in a location session and may performone or more transactions (step 3). For this location session, UE 510 maybe a target device and a positioning unit, and E-SMLC 530 may be alocation server. E-SMLC 530 may instigate one or more transactions toobtain positioning capabilities of UE 510, provide assistance data to UE510, and/or obtain positioning information from UE 510. After the firstpositioning message is received from E-SMLC 530, UE 510 may instigateone or more transactions to request for assistance data, to request forfurther assistance data, etc.

E-SMLC 530 and eNB 520 may engage in a location session and may performone or more transactions (step 4). For this location session, eNB 520may be a positioning unit, and E-SMLC 530 may be a location server.E-SMLC 530 may obtain positioning information for UE 510 from eNB 520via the location session. Steps 3 and 4 may occur in any order or inparallel. E-SMLC 530 may return a location response message to MME 540(step 5). The location response message may include any locationestimate obtained from steps 3 and 4 and/or a final positioning message,which may provide a location estimate if requested by UE 510 in step 1.If UE 510 requested location transfer to a third party, then MME 540 maytransfer the location estimate received from E-SMLC 530 to the thirdparty (step 6). MME 540 may send to UE 510 an MO-LR response messagethat may carry any final positioning message received in step 5 and/or aseparate location estimate (step 7).

For control plane location solution, a network entity (e.g., MME 540)may need to request for location service from a location server (e.g.,E-SMLC 530) before a location session can occur. For MO-LR service, atarget device (e.g., UE 510) may first send an MO-LR request message tothe network entity to request for location service. The target devicemay then wait for a response from the network entity and may thereaftersend a first positioning message to the location server. This extradelay may be avoided by having the target device include the firstpositioning message in the MO-LR request message sent to the networkentity. The network entity may then transfer this first positioningmessage to the location server in the location request message.Subsequent positioning messages may be sent more directly between thetarget device and the location server without making use of a Non AccessStratum (NAS) layer in which the MO-LR request message belongs. A finalpositioning message from the location server may be sent either directlyto the target device or via an MO-LR response message, which may reducethe total number of messages to transfer.

FIG. 6 shows a message flow 600 for a location session with multipletransactions. Message flow 600 may be used for the location session instep 3 and/or the location session in step 4 in FIG. 5. Target device110 may send an MO-LR request message to location server 130 (step 1).The MO-LR request message may carry one or more positioning messages toinstigate one or more procedures. A positioning message may include therequired QoS, whether triggered or periodic location is requested,and/or other information. Location server 130 may send a positioningmessage to request for positioning capabilities of target device 110, ifthe positioning capabilities are not received in step 1 (step 2). Targetdevice 110 may return a positioning message with its positioningcapabilities, e.g., supported positioning methods (step 3).

Location server 130 may send a positioning message to a request forpositioning information, e.g., location-related measurements for thepositioning methods supported by target device 110 (step 4). Targetdevice 110 may send a positioning message to request for assistance data(step 5). Location server 130 may return a positioning message with therequested assistance data (step 6). Location server 130 may also sendone or more follow on positioning messages with updated assistance data(not shown in FIG. 6), e.g., when triggered by changes or at a periodicinterval. Target device 110 may obtain the positioning information(e.g., measurements) and may send a positioning message with thepositioning information (step 7). Target device 110 may also send one ormore follow-on positioning messages with updated location information(not shown in FIG. 6), e.g., when triggered by changes or at a periodicinterval. Location server 130 may compute a location estimate for targetdevice 110 using the positioning information received in step 7.Location server 130 may then send an MO-LR response message, which mayinclude a positioning message and/or the location estimate, to targetdevice 110 (step 8). Location server 130 may also send one or morefollow on positioning messages with updated location estimates (notshown in FIG. 6), e.g., when triggered by certain events, or at aperiodic interval, or after receiving further positioning informationfrom the target device, etc.

FIG. 6 shows an exemplary location session with three explicittransactions A, B and C. In general, a location session may include anynumber of transactions and any type of transaction. Multipletransactions of the same type may also be performed. For example, atransaction to obtain positioning information from a target device tosupport E-CID positioning may be performed to obtain an approximatelocation, and a separate A-GNSS associated transaction may be performedin parallel or subsequently to obtain an accurate location.

FIG. 6 shows a message flow for an MO-LR service. A message flow for amobile-terminated location request (MT-LR) service may be defined withsteps 2 through 7 in FIG. 6.

As shown in FIG. 6, a number of transactions may be performed. Atransaction may involve a pair of positioning messages exchanged betweena positioning unit in a target device 110 and location server 130, asshown in FIG. 6. A transaction may also involve a single positioningmessage sent unilaterally by one entity. For example, a positioning unitin target device 110 may unilaterally provide its capabilities withoutreceiving a request for capabilities, and location server 130 mayunilaterally provide assistance data without receiving a request forassistance data. Multiple positioning messages for multiple transactionsmay be aggregated and transferred together. For example, the positioningmessages in steps 2 and 4 may be transferred together, the positioningmessages in steps 3 and 5 may be transferred together, etc.

FIG. 7 shows a design of a process 700 for supporting positioning by alocation server. The location server may obtain positioning informationfor a target device via a common positioning protocol, which may be LPPor some other positioning protocol (block 712). The location server mayreside at one of a plurality of possible entities, and the target devicemay be one of these entities. For example, the location server mayreside in a network entity or may be co-located with the target device.The location server may use the common positioning protocol regardlessof where it resides and may communicate with other entities via thecommon positioning protocol. The common positioning protocol may simplymean that the same positioning protocol is used regardless of where thelocation server resides. The location server may determine locationinformation for the target device (block 714).

In one design, the positioning information may comprise measurements forat least one reference source. For example, the location server mayobtain measurements for at least one signal from at least one satellite,or at least one base station, or at least one terminal, or the targetdevice, or some other entity, or a combination thereof The locationinformation may comprise a location estimate for the target device,which may be determined by the location server based on themeasurements. In another design, the positioning information (i) may beindicative of the location of the target device, e.g., may comprise acoarse or a fine location estimate, or (ii) may comprise measurements ofreferences sources that can be received at the location of the targetdevice. The location information may comprise assistance data determinedby the location server based on the positioning information. In yetanother design, the location information may comprise assistance data,and the positioning information may comprise measurements made based onthe assistance data. In general, the positioning information maycomprise measurements, a location estimate, etc. The locationinformation may comprise a location estimate, assistance data, etc. Thetwo steps in FIG. 7 may be performed in the order shown in FIG. 7, or inthe opposite order. The location information may be determined based onthe positioning information, or vice versa.

In one design, a positioning unit for the target device may determinethe positioning information, e.g., make measurements. The positioningunit may reside at one of a second plurality of possible entities, andthe target device may be one of these entities. The location server maycommunicate with the positioning unit via the common positioningprotocol. For example, the location server may exchange capabilities, orassistance data, or location information, or a combination thereof withthe positioning unit via the common positioning protocol.

FIG. 8 shows a design of a process 800 for supporting positioning by anentity, which may be a target device, or a positioning unit, or someother entity. The entity may send positioning information for a targetdevice to a location server via a common positioning protocol (block812). The location server may reside at one of a plurality of possibleentities and may use the common positioning protocol regardless of whereit resides. The target device may be one of the plurality of possibleentities. The entity may receive location information for the targetdevice from the location server (block 814).

In one design, the positioning information may comprise measurements forat least one reference source, and the location information may comprisea location estimate for the target device determined by the locationserver based on the measurements. In another design, the positioninginformation may comprise measurements of references sources that can bereceived at the location of the target device, and the locationinformation may comprise assistance data determined by the locationserver based on the positioning information. In yet another design, thelocation information may comprise assistance data, and the positioninginformation may comprise measurements made based on the assistance data.In this design, block 812 may occur after block 814.

In one design, the entity may measure at least one signal from at leastone reference source to obtain the measurements. In one design, the atleast one reference source may comprise at least one satellite, or atleast one base station, or at least one terminal, or a combinationthereof. In this design, the measurements may be made at the targetdevice. In another design, the at least one reference source maycomprise the target device and possibly other reference sources. In thisdesign, the measurements may be made at a positioning unit that isexternal to the target device.

FIG. 9 shows a design of a process 900 for supporting positioning by anentity, which may be a location server, a positioning unit, a targetdevice, or some other entity. The entity may exchange (e.g., send orreceive) a plurality of positioning messages transported together in onemessage transaction (block 912). In one design, the entity may send theplurality of positioning messages as linked messages or in a singlecontainer message. In another design, the entity may receive theplurality of positioning messages, which may be sent as linked messagesor in a single container message. The entity may perform positioningbased on the plurality of positioning messages (block 914).

In one design, the plurality of positioning messages may be sent with anMO-LR message by the target device to initiate positioning. In anotherdesign, the plurality of positioning messages may be sent by a locationserver and may comprise (i) a first positioning message carryingassistance data and (ii) a second positioning message requesting forlocation information. In yet another design, the plurality ofpositioning messages may be sent to the location server (e.g., by thepositioning unit or the target device) and may comprise (i) a firstpositioning message requesting for assistance data and (ii) a secondpositioning message carrying measurements. The plurality of messages mayalso include some other combination of messages.

In one design, each of the plurality of positioning messages may be ofone of a plurality of message types, which may include a requestcapabilities message type, a provide capabilities message type, arequest assistance data message type, a provide assistance data messagetype, a request location information message type, and a providelocation information message type. The plurality of positioning messagesmay include positioning messages of at least two message types.

FIG. 10 shows a design of a process 1000 for supporting positioning byan entity, which may be a location server, a positioning unit, a targetdevice, or some other entity. The entity may exchange a positioningmessage comprising a first part and a second part for a particulartransaction type (block 1012). The first part may comprise firstinformation for positioning defined by a first organization, and thesecond part may comprise second information for positioning defined by asecond organization. For example, the first organization may comprise3GPP or some other organization. The second organization may comprise3GPP2, OMA, IETF, IEEE, a network operator, an equipment vendor, or someother organization. The entity may perform positioning based on thepositioning message (block 1014).

In one design of block 1012, the entity may be a target device sendingthe positioning message to, or receiving the positioning message from, alocation server. In another design, the entity may be a location serversending the positioning message to, or receiving the positioning messagefrom, a target device.

In one design of block 1014, the entity may determine assistance data ora location estimate based on the first information (e.g., measurements)in the first part and the second information (e.g., more measurements,or a coarse location estimate) in the second part. In another design,the entity may make measurements based on the first information (e.g.,assistance data for satellites) in the first part and the secondinformation (e.g., assistance data for base stations) in the secondpart.

FIG. 11 shows a design of a process 1100 for supporting positioning byan entity, which may be a location server, a positioning unit, a targetdevice, or some other entity. The entity may exchange a measurement dataunit applicable for a first plurality of positioning methods, with eachof the first plurality of positioning methods being associated with adifferent set of applicable measurement data units (block 1112). Forexample, the exchanged measurement data unit may be MDU 2 in FIG. 3, thefirst plurality of positioning methods may include PMa and PMb,positioning method PMa may be associated with a first set of MDUs 1, 2and 3, and positioning method PMb may be associated with a second set ofMDUs 2 and 3. The entity may perform positioning based on the exchangedmeasurement data unit and in accordance with a positioning method, whichmay be one of the first plurality of positioning methods (block 1114).

Alternatively or additionally, the entity may exchange an assistancedata unit applicable for a second plurality of positioning methods, witheach of the second plurality of positioning methods being associatedwith a different set of applicable assistance data units (block 1116).The entity may perform positioning based on the exchanged assistancedata unit and in accordance with the positioning method, which may beone of the second plurality of positioning methods (block 1118).

In general, only shared measurement data units may be supported, or onlyshared assistance data units may be supported, or both sharedmeasurement and assistance data units may be supported. If only sharedmeasurement data units are supported, then blocks 1112 and 1114 may beperformed, and blocks 1116 and 1118 may be omitted. If only sharedassistance data units are supported, then blocks 1116 and 1118 may beperformed, and blocks 1112 and 1114 may be omitted. If both sharedmeasurement and assistance data units are supported, the blocks 1112 to1118 may be performed.

FIG. 12 shows a block diagram of a design of target device 110, a basestation 122, and location server 130. Target device 110 may be a UE, aSET, etc. Location server 130 may be an SMLC, an E-SMLC, an SLP, etc.Positioning unit 120 may reside in target device 110, base station 122,or some other entity. Reference source 140 may be part of base station122, or a satellite, or some other entity. For simplicity, FIG. 12 showsonly one controller/processor 1220, one memory 1222, and onetransmitter/ receiver (TMTR/RCVR) 1224 for target device 110, only onecontroller/processor 1230, one memory 1232, one transmitter/receiver1234, and one communication (Comm) unit 1236 for base station 122, andonly one controller/processor 1240, one memory 1242, and onecommunication unit 1244 for location server 130. In general, each entitymay include any number of processing units (processors, controllers,etc.), memories, transmitters/receivers, communication units, etc.

On the downlink, base station 122 may transmit data, signaling, andpilot to terminals within its coverage area. These various types ofinformation may be processed by processing unit 1230, conditioned bytransmitter 1234, and transmitted on the downlink. At target device 110,downlink signals from base station 122 and other base stations may bereceived and conditioned by receiver 1224 and further processed byprocessing unit 1220 to obtain various types of information. Processingunit 1220 may perform process 800 in FIG. 8, process 900 in FIG. 9,process 1000 in FIG. 10, process 1100 in FIG. 11, and/or other processesfor the techniques described herein. Memories 1222 and 1232 may storeprogram codes and data for target device 110 and base station 122,respectively. On the uplink, target device 110 may transmit data,signaling, and pilot to base station 122. These various types ofinformation may be processed by processing unit 1220, conditioned bytransmitter 1224, and transmitted on the uplink. At base station 122,the uplink signals from target device 110 and other terminals may bereceived and conditioned by receiver 1234 and further processed byprocessing unit 1230 to obtain various types of information from theterminals. Base station 122 may directly or indirectly communicate withlocation server 130 via communication unit 1236.

Within location server 130, processing unit 1240 may perform processingto support location services and positioning for terminals. For example,processing unit 1240 may perform process 700 in FIG. 7, process 800 inFIG. 8, process 900 in FIG. 9, process 1000 in FIG. 10, process 1100 inFIG. 11, and/or other processes for the techniques described herein.Processing unit 1240 may also compute location estimates for targetdevice 110, provide location information, etc. Memory 1242 may storeprogram codes and data for location server 130. Communication unit 1244may allow location server 130 to communicate with base station 122and/or other network entities. Location server 130 and target device 110may exchange positioning messages via base station 122 and other networkentities (not shown).

Positioning unit 120 may reside in terminal 110, or base station 122, orlocation server 130. In this case, the processing by positioning unit120 may be performed by processing unit 1220, 1230, or 1240,respectively. Positioning unit 120 may also be external to the entitiesshown in FIG. 12. In this case, positioning unit 120 may include one ormore processing units (processors, controllers, etc.), memories,transmitters/receivers, communication units, etc., that can perform therequired functions.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

Position determination techniques described herein may be implemented inconjunction with various wireless communication networks such as awireless wide area network (WWAN), a wireless local area network (WLAN),a wireless personal area network (WPAN), and so on. The term “network”and “system” are often used interchangeably. A WWAN may be a CodeDivision Multiple Access (CDMA) network, a Time Division Multiple Access(TDMA) network, a Frequency Division Multiple Access (FDMA) network, anOrthogonal Frequency Division Multiple Access (OFDMA) network, aSingle-Carrier Frequency Division Multiple Access (SC-FDMA) network, aLong Term Evolution (LTE) network, a WiMAX (IEEE 802.16) network and soon. A CDMA network may implement one or more radio access technologies(RATs) such as cdma2000, Wideband-CDMA (W-CDMA), and so on. Cdma2000includes IS-95, IS-2000, and IS-856 standards. A TDMA network mayimplement Global System for Mobile Communications (GSM), DigitalAdvanced Mobile Phone System (D-AMPS), or some other RAT. GSM and W-CDMAare described in documents from a consortium named “3rd GenerationPartnership Project” (3GPP). Cdma2000 is described in documents from aconsortium named “3rd Generation Partnership Project 2” (3GPP2). 3GPPand 3GPP2 documents are publicly available. A WLAN may be an IEEE802.11x network, and a WPAN may be a Bluetooth network, an IEEE 802.15x,or some other type of network. The techniques may also be implemented inconjunction with any combination of WWAN, WLAN and/or WPAN.

A satellite positioning system (SPS) typically includes a system oftransmitters positioned to enable entities to determine their locationon or above the Earth based, at least in part, on signals received fromthe transmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chipsand may be located on ground based control stations, user equipmentand/or space vehicles. In a particular example, such transmitters may belocated on Earth orbiting satellite vehicles (SVs). For example, a SV ina constellation of Global Navigation Satellite System (GNSS) such asGlobal Positioning System (GPS), Galileo, Glonass or Compass maytransmit a signal marked with a PN code that is distinguishable from PNcodes transmitted by other SVs in the constellation (e.g., usingdifferent PN codes for each satellite as in GPS or using the same codeon different frequencies as in Glonass). In accordance with certainaspects, the techniques presented herein are not restricted to globalsystems (e.g., GNSS) for SPS. For example, the techniques providedherein may be applied to or otherwise enabled for use in variousregional systems, such as, e.g., Quasi-Zenith Satellite System (QZSS)over Japan, Indian Regional Navigational Satellite System (IRNSS) overIndia, Beidou over China, etc., and/or various augmentation systems(e.g., an Satellite Based Augmentation System (SBAS)) that may beassociated with or otherwise enabled for use with one or more globaland/or regional navigation satellite systems. By way of example but notlimitation, an SBAS may include an augmentation system(s) that providesintegrity information, differential corrections, etc., such as, e.g.,Wide Area Augmentation System (WAAS), European Geostationary NavigationOverlay Service (EGNOS), Multi-functional Satellite Augmentation System(MSAS), GPS Aided Geo Augmented Navigation or GPS and Geo AugmentedNavigation system (GAGAN), and/or the like. Thus, as used herein an SPSmay include any combination of one or more global and/or regionalnavigation satellite systems and/or augmentation systems, and SPSsignals may include SPS, SPS-like, and/or other signals associated withsuch one or more SPS.

The methodologies described herein may be implemented by various meansdepending upon the application. For example, these methodologies may beimplemented in hardware, firmware, software, or any combination thereof.For an implementation involving hardware, the processing units may beimplemented within one or more application specific integrated circuits(ASICs), digital signal processors (DSPs), digital signal processingdevices (DSPDs), programmable logic devices (PLDs), field programmablegate arrays (FPGAs), processors, controllers, micro-controllers,microprocessors, electronic devices, other electronic units designed toperform the functions described herein, or a combination thereof.

For an implementation involving firmware and/or software, themethodologies may be implemented with modules (e.g., procedures,functions, and so on) that perform the functions described herein. Anymachine-readable medium tangibly embodying instructions may be used inimplementing the methodologies described herein. For example, softwarecodes may be stored in a memory and executed by a processing unit.Memory may be implemented within the processing unit or external to theprocessing unit. As used herein the term “memory” refers to any type oflong term, short term, volatile, nonvolatile, or other memory and is notto be limited to any particular type of memory or number of memories, ortype of media upon which memory is stored.

If implemented in firmware and/or software, the functions may be storedas one or more instructions or code on a computer-readable medium.Examples include computer-readable media encoded with a data structureand computer-readable media encoded with a computer program.Computer-readable media can take the form of an article of manufacture.Computer-readable media includes physical computer storage media. Astorage medium may be any available medium that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage, semiconductor storage, or other storagedevices, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer; disk and disc, as used herein, includes compactdisc (CD), laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

In addition to storage on computer-readable medium, instructions and/ordata may be provided as signals on transmission media included in acommunication apparatus. For example, a communication apparatus mayinclude a transceiver having signals indicative of instructions anddata. The instructions and data are configured to cause one or moreprocessing units to implement the functions outlined in the claims. Thatis, the communication apparatus includes transmission media with signalsindicative of information to perform disclosed functions. At a firsttime, the transmission media included in the communication apparatus mayinclude a first portion of the information to perform the disclosedfunctions, while at a second time the transmission media included in thecommunication apparatus may include a second portion of the informationto perform the disclosed functions.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not intended to be limited to theexamples and designs described herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method for positioning a target device,comprising: receiving, from a location server, a Request LocationInformation message that indicates at least a first positioning methodfrom a plurality of positioning methods, the plurality of positioningmethods including the first positioning method and a second positioningmethod, wherein the Request Location Information message comprises afirst field containing information specific to the first positioningmethod and a second field containing common parameters, wherein thecommon parameters are applicable to the first positioning method and thesecond positioning method and also applicable to all positioning methodsindicated in the Request Location Information message, and wherein thecommon parameters comprise a quality-of-service (QoS), an indication ofwhether periodic location information is requested, an indication ofwhether triggered location information is requested, or any combinationthereof, and wherein the plurality of positioning methods comprises: anuplink time difference based positioning method, a downlink timedifference based positioning method, a propagation time basedpositioning method, a signal direction based positioning method, a pathloss based positioning method, a radio frequency pattern matchingpositioning method, assisted Global Navigation Satellite Systempositioning method, enhanced cell identity positioning method or anycombination thereof; and performing positioning in response to theRequest Location Information message.
 2. The method of claim 1, whereinperforming positioning in response to the Request Location Informationmessage comprises determining a location estimate for a location of thetarget device.
 3. The method of claim 2, further comprising: sending thelocation estimate to the location server, wherein the location estimateis a coarse estimate, and wherein the location server determines a finelocation estimate based on the coarse estimate.
 4. The method of claim1, further comprising: periodically sending updated location informationto the location server based on determining that the common parameterscomprise the indication that periodic location information is requested.5. The method of claim 1, wherein the common parameters included in theRequest Location Information message further comprise a location typefor a terminal-assisted positioning method, a location type for aterminal-based positioning method, or both.
 6. The method of claim 5,wherein the common parameters included in the Request LocationInformation message further comprise a location type for at least one ofthe following positioning methods: assisted Global Navigation SatelliteSystem, observed time difference, enhanced observed time difference,observed time difference of arrival, and advanced forward linktrilateration.
 7. The method of claim 1, wherein the Request LocationInformation message is one of a plurality of positioning messagesexchanged between the location server and a recipient of the RequestLocation Information message, and wherein the plurality of positioningmessages comprises one or more of: a Request Capabilities message torequest capabilities of a receiving entity for a positioning protocoland positioning methods, a Provide Capabilities message to providecapabilities of a sending entity for a positioning protocol andpositioning methods, and a Provide Location Information message toprovide location information.
 8. The method of claim 7, furthercomprising: receiving a Request Capabilities message from the locationserver; and transmitting, in response to the Request Capabilitiespositioning message, capabilities of the target device to the locationserver in a Provide Capabilities message.
 9. The method of claim 8,wherein the capabilities include an indication of one or morepositioning methods supported by the target device and the capabilitiesof the target device for each positioning method supported by the targetdevice.
 10. An apparatus for positioning a target device, comprising: atleast one processing unit; and a memory coupled to the at least oneprocessing unit, the memory storing instructions that when executed bythe at least one processing unit cause the at least one processing unitto: receive, from a location server, a Request Location Informationmessage that indicates at least a first positioning method from aplurality of positioning methods, the plurality of positioning methodsincluding the first positioning method and a second positioning method,wherein the Request Location Information message comprises a first fieldcontaining information specific to the first positioning method and asecond field containing common parameters, wherein the common parametersare applicable to the first positioning method and the secondpositioning method and also applicable to all positioning methodsindicated in the Request Location Information message, and wherein thecommon parameters comprise a quality-of-service (QoS), an indication ofwhether periodic location information is requested, an indication ofwhether triggered location information is requested, or any combinationthereof, and wherein the plurality of positioning methods comprises: anuplink time difference based positioning method, a downlink timedifference based positioning method, a propagation time basedpositioning method, a signal direction based positioning method, a pathloss based positioning method, a radio frequency pattern matchingpositioning method, assisted Global Navigation Satellite Systempositioning method, enhanced cell identity positioning method or anycombination thereof; and perform positioning in response to the RequestLocation Information message.
 11. The apparatus of claim 10, whereinperforming positioning in response to the Request Location Informationmessage comprises determining a location estimate for a location of thetarget device.
 12. The apparatus of claim 11, wherein the instructionsfurther cause the at least one processing unit to: send the locationestimate to the location server, wherein the location estimate is acoarse estimate, and wherein the location server determines a finelocation estimate based on the coarse estimate.
 13. The apparatus ofclaim 10, wherein the instructions further cause the at least oneprocessing unit to: periodically send updated location information tothe location server based on determining that the common parameterscomprise the indication that periodic location information is requested.14. The apparatus of claim 10, wherein the common parameters included inthe Request Location Information message further comprise a locationtype for a terminal-assisted positioning method, a location type for aterminal-based positioning method, or both.
 15. A non-transitorycomputer-readable medium storing instructions for positioning a targetdevice, wherein the instructions when executed by the one or moreprocessors cause the one or more processors to: receive, from a locationserver, a Request Location Information message that indicates at least afirst positioning method from a plurality of positioning methods, theplurality of positioning methods including the first positioning methodand a second positioning method, wherein the Request LocationInformation message comprises a first field containing informationspecific to the first positioning method and a second field containingcommon parameters, wherein the common parameters are applicable to thefirst positioning method and the second positioning method and alsoapplicable to all positioning methods indicated in the Request LocationInformation message, and wherein the common parameters comprise aquality-of-service (QoS), an indication of whether periodic locationinformation is requested, an indication of whether triggered locationinformation is requested, or any combination thereof, and wherein theplurality of positioning methods comprises: an uplink time differencebased positioning method, a downlink time difference based positioningmethod, a propagation time based positioning method, a signal directionbased positioning method, a path loss based positioning method, a radiofrequency pattern matching positioning method, assisted GlobalNavigation Satellite System positioning method, enhanced cell identitypositioning method or any combination thereof; and perform positioningin response to the Request Location Information message.
 16. Thenon-transitory computer-readable medium of claim 15, performingpositioning in response to the Request Location Information messagecomprises determining a location estimate for a location of the targetdevice.
 17. The non-transitory computer-readable medium of claim 16,wherein the instructions further cause the one or more processors to:send the location estimate to the location server, wherein the locationestimate is a coarse estimate, and wherein the location serverdetermines a fine location estimate based on the coarse estimate. 18.The non-transitory computer-readable medium of claim 15, wherein theinstructions further cause the one or more processors to: periodicallysend updated location information to the location server based ondetermining that the common parameters comprise the indication thatperiodic location information is requested.
 19. The non-transitorycomputer-readable medium of claim 15, wherein the common parametersincluded in the Request Location Information message further comprise alocation type for a terminal-assisted positioning method, a locationtype for a terminal-based positioning method, or both.